Issue:
Modbus communication on a Uniflair unit.

Product line:
Uniflairl.

Environment:
All Models and Serial Numbers.

Cause:
Install.

Resolution:
MODBUS RTU

Scenario 1

Modbus is a communication protocol very famous and used all over the world. It’s quite easy and not so structured.

•          It has been developed at the end of ’70 from Modicom

•          The communication is multidrop, with Master and Slaves

•          It is not used only with industrial application

•          Serial communication: RS232 or RS485 half duplex

•          Protocol type: Modbus RTU (1 byte = 2 hexadecimal words) and Modbus ASCII (1 byte = 2 ASCII  words).

Configurable Baud rate (max 19200)

The units, all fitted with the serial card, are connected:

• each unit with the RS485 cable;

• last unit with the final resistor;

• first unit with the Gateway.

To realize a local net to be connected to a BMS working with Modbus, it’s necessary:

• 1 gateway LBM every 16 units;

• 1 serial card RS485 for every controller;

• 1 terminal line (120 Ω);

• PC for the gateway configuration.

Scenario 2

Units fitted with pCO1, upCOxs

To realize a local net to be connected to a BMS working with Modbus, it’s necessary:

• 1 RS485 serial card for every controller;

• 1 terminal line (120 Ω);

• PC for the gateway configuration.

Publié pour: Schneider Electric Algeria